paid up handed over account but still no letter

Hi, I had a cell c contract in 2010, in which I was paying, due to an unstable employment history, I was unable to pay causing my account to be handed over to RL Daly Attorneys for collection. In 2015, I started making arrangements with collections regarding the account in which I've paid the account off in December 2015, after settling the account, I contacted RL Daly in January again as I saw its over 2 weeks without a response from them. I was advised from them that the account is closed on their side and that they awaiting instruction from Cell C to finalize the file in order for them to send me a paid up letter. Please can I have an update as to what is going on because I don't want this account to incur more costs knowing that I've paid it off already.