unhelpful regarding paid up letter

I had an account with Nashua mobile that was handed over to pholosa. Account was settled in june 2014. Been pushed from pillar to post around settlement letter. Consultants are unhelpful. Do not keep to the promises made. Been promised a letter since june and now am told to chase the letter with nashua mobile which has closed down. Where does it leave me as a consumer.i have paid every cent owed to these people for them to tell me that the CEO will not sign anything for nashua mobile. <br> Extremely frustrated and livid