Struggling to get invested money back since March

I have a tax free saving investment with them and had a short fall and I paid it before the end of financial i.e February. The money was never allocated my account therefore I received no interest on it .I have been sending emails calling but receiving no help since beginning of March. Towards the end of June I was told they will pay back the money I submitted all the required documents and I said I want to cancel the contract with immediate effect. Up till now I have not received a cent from them. I phoned on the 05/07/21only then they sent me the forms to complete on the 05/07/21 then I waited for the money nothing . I sent an email asking about the payment I was sent other forms to complete on the 13/07/21. Customer Service there is the worst they just don't care and they do not even respond to the emails. One has to keep on calling they could not be bothered. I even went to the branch they could not help.