Removing a default from my credit file

Good afternoon,

So I have a problem that I need your help with. It appears that I have a default on my credit file from IDmobile. Its from a sim only 30 day plan that I had over three years ago.

I never used the sim in the end as it was was bought for my business and never needed, I cancelled the DD and thought that was that, I pretty soon realised that it wasn't as simple as that when I received a letter with an outstanding amount, I paid that and thought no more of if…

Fast forward to last month and I’m informed that I can't get the mortgage that I’ve applied for due to my  (what I thought was immaculate) credit score, so I obtained a copy of it and discovered that after I had cleared my account, the monthly charge hadn't been stopped… The problem with that is that I had also moved house in that period and despite having mail redirected, I was not made aware of any outstanding balance. Despite the fact that I have even been using a new ID plan in the meantime.

I have always worked hard to maintain a good credit score, and to think that a £10 monthly sim which leads to an outstanding default amount of £35, and one of which that I was never informed of (you had my email address) is devastating when it has such an effect on a mortgage application.

If you are able to help with this then that would be great,

Thanks,

Johnny