Product: Vehicle loan or lease

My wife and I have a XXXX XXXX XXXX leased from Mazda Capital Services ( through Chase Auto Finance ). The account number is xxxxxxxxxx. The lease expired in XX/XX/XXXX and, not wanting to trade the car in yet, we reached out to Chase to apply to convert the lease to a loan. In late XXXX, Chase approved us for the loan and sent us paperwork ( Identity verification, odometer statement, powers-of-attorney, a new Note, etc. ), which we signed, notarized, and returned ( application ID xxxxxxxxxx ). We also continued making the payments as we were instructed by Chase. During this process, Chase asked if we would be interested in signing a lease extension since the lease was expired, to which we responded, no were in the process of converting the lease to a loan, and Chase seemed to be fine with that. We were never informed that signing a lease extension was absolutely required or the vehicle could be repossessed. In mid XXXX, Chase contacted us and said they didnt receive one copy of a power-of-attorney and would need to send us a whole new packet of loan paperwork which was fine and we agreed to sign and return it as soon as it was received ( we never received new paperwork ). However, on the morning of XX/XX/XXXX, we wake up to find the car gone repossessed. After hours on the phone with multiple people at Chase who all gave different explanations for the repossession, we still dont understand what we did wrong. Two different Chase representatives claimed that repo notices were sent to us via XXXX, but when we asked for the tracking number, they said, oh sorry I think it was sent via regular mail, not XXXX. However, we have not received any repo notices by mail or XXXX, or phone. In addition, the Chase lease conversion department continues to contact us to finalize the process, apparently unaware that the vehicle has been repossessed - by Chase. Weve made all payments due since day 1 including after  lease expiration ( as requested by Chase, and Chase does not dispute this ), and we were definitely in the process to convert the lease to a loan ( Chase does not dispute this ), but we find ourselves without the vehicle and not knowing what we should do at this point. In addition, the tire marks in the street indicate the vehicle was dragged away, so were nervous about what damage may have been done to the vehicle by the repo vendor. Chase claims calls were made to us at various times which we did not return, but we have no record of missed calls or voicemails. In fact, one of the representatives we spoke to on Friday, XX/XX/XXXX, ( XXXX ID # XXXX ) was doing some research and claimed to have called us to discuss the repo but the call was static-y and didnt go to voicemail ( we had to call back and eventually somehow found our way back to XXXX ), leading us to believe that other calls may have been made that didnt go through and no additional attempts were made. Clearly, the process to convert the lease to a loan is much more complicated than we anticipated, but at the end of the day, weve made the payments and have done everything ( we thought ) to convert the lease, sign a new Note, and continue making payments. Weve done everything asked by Chase, but now because we didnt understand the process due to what we consider confusing misrepresentation by Chase, we are now faced with having no vehicle and credit that will be ruined due to the repossession. Is it typical for a big financial institution like Chase to harm paying consumers by repossessing their vehicles, with no notice, due to what appears to be clerical errors during the process to convert a car lease to a loan? Again, Chase confirms the payments were made, and the loan paperwork was received, but they believe the repossession was justified? Please help. 
UPDATE : During the past few days we continue to speak with different Chase representatives ( XXXX, XXXX, XXXX, XXXX, XXXX XXXX, XXXX, just to name a few ) - no one has offered to be a single point of contact or customer advocate, which makes communication incredibly difficult - we have to explain our situation all over again with each new Chase representative. One person tells us they believe Chase should be able to complete the lease-to-loan conversion with a favorable outcome where we get the car back and move forward with the loan that's already been approved, as they've seen this situation happen before, but then the next person says theres no notes in the system of anybody saying that and theres nothing Chase can do. We receive phone calls from unknown numbers that only ring once and leave no voicemail, and when we call the number back we find that it was Chase, and we start the process all over again. Have we made the payments even after lease expiration? Yes, and Chase does not dispute that. Did we sign, notarize and return the loan paperwork that Chase sent us? Yes, and Chase does not dispute that. But we still have no idea what we did wrong, why our car was repossessed, and why we get different explanations and possible outcomes from every different person we speak with. Were starting to think that Chase representatives dial our number, intentionally let it ring only once, and hang up, then notate their system that they tried to reach us, in order to make it look like they are making an effort to resolve the situation. Obviously our main concern is the damage to our credit due to a repossession. But the secondary impacts are becoming overwhelming - we are trying to manage our family activities with our one remaining vehicle, we've spent hours/days on the phone with Chase going in circles, we now answer every call from unknown numbers as quickly as we possibly can for fear it might be Chase and we'll be penalized if we don't answer, we're losing sleep and the stress is mounting every day. One Chase representative will lead us to believe everything can be resolved but the next Chase representative says there's nothing they can do. As a consumer I've lost faith in Chase and feel completely helpless.