Hope someone can help with advice please?

In 2014 I claimed tax credits for the first time for a period of 6 months only (April 14 Oct 14)

In July 2015 I was asked to renew my tax credits, which I didn't as I was not receiving tax credits anymore (Im now aware I should have done it anyway)

Because I did not renew, HMRC have used an estimate figure of my self employment income. They have used £2562.50 but it was actually only £149.

HMRC say I owe £2,133 because they have had to calculate on their estimate self employment income. They advise I can dispute it but because I did not do my renewal it is very unlikely it will get agreed and the £2,133 will have to be paid back.

I have admitted it was my fault due to simply never claiming before and unaware I had to renew, If I had renewed and input the correct figures I would not owe anything.

Do I have a chance with this?

My fault for not knowing how the system works!

Hope someone can help.

I recieved a call from a Web Design company offering a free web design with no obligation. I agreed to the trail as their prices were competative.

I viewed the web site that they had made and I was not impressed. I told the owner that I thought it looked basic an could they change the design, which they agreed.

They changed the design and I was pleased with it. I asked them over the phone how to go ahead with this. They advised they would send me out an invoice and the process to inform my current website supplier.

I recieved the invoice, but did not pay them due to an increase in work load in my business. I recieved a text from the owner asking me to pay the invoice. I sent him a text back asking if we could put this on hold until the new year due to my workload. I got a text back saying they could delay the website start date but would require payment straight away.

I did not pay, again as I was very busy and not had time to look into it further. I then recieved a text from the owner again saying that if I did not pay by a certain date he would take legal action against me.

I then sent him an email advising that I wished to cancel the order as I did not want to work with someone who would send threatening texts like this.

I got a bit of a snotty email back to which I have not replied. I have had a couple od text messages saying they are going to take me to court plus costs and interest unless I pay the invoice. I have had a letter from him saying the same.

I do not feel I am tied into anything as I have not signed anything, and I have his orginal email which states no obligation web design. Am I correct or should I be worried?

Many Thanks in advance for all your help.