Worst business purchase I have ever made!

We have used Mamut E3 since 2005 and we're unfortunately stuck with it! We have just been told they are giving us a "free" upgrade to their Mamut ONE product with loads of bells and whistles that you can use online when away from the office. What they don't mention in all the bumf they send you (unless it’s in the small print) is the fact that the compulsory service agreement is nearly doubling in price!! The extra online functionality is extremely slow to use, limited in functionality as well pointless and unnecessary for me as I get full functionality when away from the office by logging in to my work PC from the cheap as chips and excellent LogMeIn service. But now I have to pay the service agreement for this Mamut one web based ability for all 6 members of staff even though I’m the only one who would ever need off site access! We decided to look at other options to move away from Mamut and found some good systems that seem to have moved with the times (unlike Mamut, more of that below) only to realise that if we cancel our service agreement with Mamut we will lose all our data as the software won’t run without a service agreement.
The software itself is excruciatingly slow and full bugs it takes 4 minutes to open up on my fairly powerful and newish Dell Precision pc, although a colleagues older and slower machine on the desk next to me only takes 30 seconds?? (Their tech guys can’t figure it out either and tell me to buy a new server even though there’s nothing wrong with the hardware) it also regularly crashes about 3 times a day, it also forgets which printer it should be printing various reports and invoices or delivery notes from end prints them to random printers instead it is just horrendously unstable. Each new version is a nightmare to install and always presents new problems and bugs that never seem to get ironed out.
Other than the online function that they have introduced the actual desktop version has barely changed since we started using it. There is still no automated way of emailing statements to customers, you have to manually create each email. The webshop function is pathetic. It is supposed to seamlessly connect and sync with Microsoft outlook however that just makes outlook crash. The stock control is suspiciously inaccurate and creates weird anomalies depending which part of the program you’re in. Your account manager at Mamut seems to change regularly as I presume they get cheesed off with angry customers and leave. I can’t recommend this to anyone; buy sage or an abacus or anything else.