Worst company

I have an account with mobicred and had failed to make payment and they handed over my account to a debt collector company. I made a pay on Monday and forgot to put the reference number and I called mobicred to allocate the money to my account and I was told that they can’t I must contact the debt collector and send them the proof of payment. I’ve been trying to get hold of the debt collector for 3 days and I am unable to get hold of them so I decided to inform mobicred about this and the lady was rude and told me there’s nothing she can do. I told her I will not be able to continue paying the account until the money I paid is allocated she said “that’s up to me”