Incompetence or theft ?

I am executor of my late mother’s estate. I am waiting now for three and a half months to get access to her account. I was originally told it would take up to six weeks to finalize the matter. Every time I go to the branch, and I have made many trips there, they phone the estate late department and are apparently given an excuse as to why it hasn’t happened, sometimes the same excuse of not having received a document after it has been sent different times. When I called that department and spoke to the team leader she undertook to have payment made. When it wasn’t and I called back she had gone home but would phone me . When she didn’t I waited a few days and went back to the branch to be told that the same document was not there and then it was but they were busy so I would have to wait another week. I can’t help thinking that they are deliberately delaying things while they are earning interest on a large amount of money while paying nothing and deducting fees from the account I was made to open to receive the money. They will not tell me who I can contact to sort the matter out for once and for all, nor will they tell me who I can speak to to claim interest on the money I should be earning interest on for the benefit of the beneficiaries. This is either gross incompetence or a deliberate strategy and I can’t help believing it is the latter.