GO2bank complaint: Fraudulent tactics

On march 28th I filed a dispute with Go2bank which is parented by green dot. I was informed that so long as I send in dispute forms within 10 days of the date of dispute I will be eligible for provisional credit while the investigation is taking place. Today I called in to find out what was going on as the letter was sent in17 days ago and it would be impossible even with snail mail not to have gotten it. They informed me that they didn’t and when i request for a supervisor to give me the information I’m told they can’t transfer me over and I am coincidently hung up on 11 times in a row with perfect service. At this point I’ve been refused help and I’m convinced that they have fabricated the fact that they did not receive my letter. I also asked multiple times to be given the information of who regulates Go2bank and was refused to be given the answer. I’m pretty sure as a banking institution they are obligated to share that information with me but would not. I need the money from my dispute or the provisional credit and I need this to be examined further as the tactics used by this bank are outrageous.