Product: Vehicle loan or lease

We have two very critical complaints. 
Part 1. GM Financial 's online payment system consistently was problematic which caused payments to be skewed, unrecorded, or improperly assigned to the correct month. We were unaware of the discrepancies in their billing system for the following reasons : their online system was difficult to navigate and we were unable to review monthly payments as assigned per month ; was often offline/unavailable due to their IT issues ; no matter when we paid every month, their online system consistently reported that we owed a month 's payment ; numerous calls to Customer Support were unproductive- they shared inaccurate information, promised numerous times to mail hard copies of our monthly reports which we never received, and failed to fulfill other promises such as correcting information held by the credit reporting agencies. 
To summarize the below information : our credit has been negatively impacted by two false cases of unrecorded payments, which were paid, but which GM Financial used to then report on our credit history a total of 6 'over 30 days ' late payments in XXXX and XXXX. The following are facts that we can prove : XXXX. XXXX XXXX we made a payment within 30 days and we were never informed there was an issue with that payment either online or by mail. GM Financial, unbeknownst to us, then took our XXXX payment and applied to XXXX, and took our XXXX payment and applied it to XXXX, causing all three months to be recorded as over 30 days late. After 3 months of recording incorrectly, they corrected their mistake in XX/XX/XXXX. GM Financial, however, never corrected our payment history report and listed those 3 months XXXX XXXX, XXXX, XXXX XXXX as all being over 30 days late to all credit reporting agencies. 
XXXX. XXXX XXXX the EXACT same situation occurred in XXXX. XX/XX/XXXX payment not recorded, then XXXX 's payment was applied to XXXX, and XXXX 's payment was applied to XXXX. GM Financial, unbeknownst to us, corrected their mistake again but failed to edit any of their credit reporting mistakes. 
Other than being continually confused by their online/hard copy payment statements, we were unaware that they had reported these inaccuracies due to their own failed system until we went to lease a new car and our credit report was revealed. 
Since that time, we have had two lengthy conversations with GM Financial representatives that have had numerous short ones that have yielded no positive results. 
Part 2 : We are contesting GM Financial 's report that there was excessive damage and wear to the car when it was returned at the end of the lease. 
Before returning our leased vehicle, we took it to a body shop to have any damage repaired. The day we went to the dealer to return the leased car, no representative was there to review and check in the car. We requested that a dealer rep be present to look the car over but were told that they would contact us when they were ready for inspection and allow us to be present. We received no notification. The report received by GM FInancial showed damage that was not present when we released the car. Furthermore, after reviewing the photograph, it is obvious to us that it was not our car in the photograph due to the following : 1. in the photograph, there was a picture of the vehicle 's engine compartment and there were numerous oak leaves packed under the hood- we have no oak trees on our property and furthermore, we were diligent to keep the engine compartment clean when the vehicle was in our possession ; 2XXXX the front bumper was replaced immediately prior to returning the vehicle and the picture revealed a great deal of dust and dirt that could not have been accumulated in the short week 's time prior to its return to the dealer ; 3XXXX the body shop prior to releasing the vehicle, corrected any damage and the damage shown in the photograph did not exist when we dropped off our vehicle ; 4. there was an identical car in the background of the photograph which we believe was, in fact, our leased vehicle. 
Bank statements and GMFinancial website statement screenshots that demonstrate and prove the inconsistencies can be provided by request as needed to resolve and support our dispute.