i signed it on 18th and then cancelled....signing it and sending off to post on 25th

please can somebody advise me. a rep for safestyle knocked at my door at about 1800hrs on a monday night. i then agreed to have a quote as i do actually need new windows and doors. i was then telephoned after about 10 mins and another guy came round for the quote. he was polite and i had no real drama apart from him not leaving til nearly 2230hrs. i explained to him that i needed lintels piut in a couple of windows as atthe moment i have stone surrounds andhe advisedme strongly that the stoned surrounds would be better, but then said to speak to the surveyor when he comes out. i paid 80 for surveyor to come out on the following friday, who was also polite. i expressed my concerns about leaving the stne surround in and he also advised it would be better, i am a sigle fulltime working mum, and at the time had my 2 toddlers plying me up so he was not really getting my full attention. after he had left, i got speakingt to one of my neighbours and they showed me photos of when they had the surrounds left in (since then thay have had them removed) and i was not happy at the size of all the windows as they were tiny. so i cancelled by post my order, having signed the form at 2200hrs on the monday night i stupidly thought that my 7 days was working days and i was well within my time. i had signedthe cancellation on the following monday (a day out). i have since had a phonecall from them, so i explained my reason, and they said they would not put lintels in as i did not need them and that i can not get out of th contract. i have told them quite firmly that i do not wish to continue but after an average of 20 missed phonecalls on mob and equal amounts on house phone, daily i called them.....the guy was rude and i was all of a fluster and agin ended up telling him i did not want windows doing, he said it was tough i could not cancel contract and so i just put phone down. i have not heard from them now, which worries me more as i think they are going to just turn up on the installation date.....or recieve a letter summonsing me to court.....does anyone have any advise