The Company CVS helped us to reduce our rates and we agreed on paying them a fee of 50% on whatever amount they would help us save. When we agreed to the contract, We were told that if we left the premisis we would not have to make any further payments to CVS. So a monthly Invoicing Period was agreed over the phone by CVS. However, they now want payment for the whole year in one payment and also want to charge us interest on the previous months saying that we should be paying annually and not monthly. We have also been threatend with a Winding up petition should we not pay the total amount which we are willing to pay but minus the interest they want to charge us which works out as nearly £500. I just want to know if this interest (which is stated as 'contractual interest') has been charged lawfully as there was nothing in the terms and conditions stating this charge.