Worst experience ever

Don't know what more to do. Been calling Mondo Mtn on a weekly basis since Oct 2021 and my matter still hasn't been resolved. Mondo needs to waiver a cancellation fee(and pass credit) that I've been billed for and Mtn can do nothing on their end until Mondo have submitted the necessary request. I've requested call backs from managers and have received nothing. Consultants have promised to call me with feedback and I have not received a single call. Apart from ONE call I received on the 31 Dec 2021, from a supervisor who promised to get this resolved and still nothing. I unfortunately would not be able to recommend Mondo.