Complaint sub-issue: Credit card company isn't resolving a dispute about a purchase on your statement

XX/XX/XXXX my wife took our car to XXXX for an oil change. In addition to changing the oil, they also drained, flushed and refilled the transmission. In the process of doing so, one of the transmission seals was blown out and the transmission incurred a notable link. 
Upon returning home ( XXXX hours away ) I noticed transmission fluid on the garage floor. I called the XXXX XXXX, spoke with the manager and was directed to take it to our local XXXX store here, which I did. They confirmed the leak, took some pictures, and told me there was nothing they could do. They also noted that the fluid level was reading full- even after driving XXXX hours+ with a substantive leak- meaning the transmission was overfilled. 
I communicated again with XXXX, the manager at the store in XXXX and indicated the situation, he at first was resistant to try and help out, indicating they didn't warranty work for any vehicles that had over XXXX miles on them. As I was running into a brick wall, I took the vehicle to a local service company who replaced the damaged seal and charged me XXXX in the process. 
I then communicated again with XXXX who began to come around based on the information provided by the company that repaired the damage. He said he would work with me to try and resolve the situation. I continued to check in with XXXX who said he was working on my behalf to resolve the situation. This took a number of weeks as while important to resolve, I was willing to let the XXXX process work. At the end of this XXXX indicated his regional manager XXXX was the hold up and was not agreeable to work with me on this. At this point XXXX suggested I file a claim with XXXX corporate as a way to get this cleared up. 

This was much later in the process, I called on XXXX and spoke to " XXXX '' who took my information and gave me a claim number XXXX. I called back a few weeks later as still nothing had happened and on XXXX spoke with XXXX who indicated is was up to XXXX the regional manager to get this resolved and he was supposed to have called me. Never happened. 

I called yet again on XX/XX/XXXX and the rep at that point got XXXX on the phone and he proceeded to tell me I was XXXX in terms of getting this resolved- their equipment is infallible and that was that. 

After this I got on the Citi website to file a dispute, only to find I had to call it in to get things processed. I called and the rep I spoke with said she couldn't process anything unless I sent in a letter and documentation regarding the problem. I did that and didn't hear anything back. I called after a week or so and spoke with another rep who indicated my paperwork had been received, but for whatever reason had not been entered into their " system ''. He indicated would get that covered and for me to check back. Again, nothing... 

I called today and found out a letter had been supposedly mailed to me ( never received ) that stated that Citi could not process the dispute due to the time that had elapsed. 

Sooo, I followed the process and in good faith was working with XXXX with the expectation they would make things right. They damaged what up until that point had been a perfectly functioning leak free vehicle. In addition to charging me for the privilege of them having XXXX things up, I had to shell out another XXXX to fix what they had damaged. 

Because I believed there would be some satisfaction with the process, I did not file a dispute. When I did, Citi indicated there was a process, which ultimately there was not- due to the timeframe- which only occurred as I was working to resolve the issue with the merchant. Thanks to them for having me spin wheels for no reason.