Victim of a Sales Trick - Any Advice Appreciated!

Fellow Practitioners,

I was pursuaded to accept a 30 Day trial package by my existing website hosting co. 1and1.  They added an expensive package to my account even after me resisting during phone conversation.  However, I accepted after being told that it is a no-obligation package and the sales person will call back before the expiry of 30 days which didn't happen.  Not hearing from anyone, I emailed the co. requesting a cancellation on 24th day which was not done until 30 days are passed and an invoice was for the next 3 months. Finally I had to call and scream to get it cancelled altogether. However, they want me to pay for the invoice they issued and I personally do not want to pay since I have an email evidence requesting the cancellation on 24th day of the 30 day trial period and that I didn't use and didn't want to take up the offer.  I requested them to reconsider but they'll not do so.  What avenues are there for accountants or similar professionals to address such issues to avoid debt collection and bad credit rating for my practice.

Appreciate any helpful suggestions!

0622228