Hello again!

i have a few loans all of which are up to date and not in arrears and decided to pay all but one of them off. One of the loans was to “livelend” and I paid via their website selecting settlement figure which I paid off in its entirety. Several days later on bank holiday weekend I receive a phone call saying I have missed a payment of £84.39. I explained I was up to date and had made a full and final payment several days earlier. I had made March payment several days late but website shows I paid double in April. I was told the people I needed to speak to didn’t work bank holiday weekends. I spent Wednesday chasing them up and eventually someone spoke to me and said he would make enquiries and get back to me. On Friday I received a call in which he said he listened to previous phone call and can see the member of staff wasn’t very helpful, also he admitted to me that I selected early settlement figure when I made payment of £2614.57. However due to something with regards to their software it missed out £84.39. Am I legally obliged to pay this money? Also if I am not how do I prevent the company giving me a bad credit reference.