Sprint They charged me a plan that I don’t have anymore and don’t want to refund San diego California

I contracted a Sprint plan in February and after 4 I cancele this plan because the salesperson call me and said he had told me the wrong price so I my bill would be more than 100$ (initially would be 80$ and then changed to 128$).

One month later (my plan was already canceled) I received a message from my bank saying that I was negative because Sprint charged me about this plan that I had already canceled. 

Because of this, the bank charged me an overdraft (35$) because I wasn’t expecting this and I didn't have money on my account.

In this past 2 months, I spoke with many agents (more than 10 times) and they said the same thing: that I would be refunded in 163$ (128$ plan plus the overdraft 35$). I already had the 128$ but I am waiting for the 35$ related to the overdraft. 

I call Sprint every week asking about this and they say that they will call me with an answer about how they will refund me but has been more than 2 months that I am waiting someone to call me and solve my problem.