Net Enterprise payment problem?

I originally registered with Net Enterprise and did this with no problem and paid the first and second cotisiation online, then they changed me to trimestrielle instead of monthly - it threw me a bit but I decided it was actually a better way to pay so I paid the forth trimestrielle online successfully. However, that’s when the problems began, the site would not allow me access to pay for the first trimestrielle and I panicked and visited St Brieuc RSI and paid a cheque to them (end of March), they gave me the info that I had not been paying my tax upfront, (which I had) and tried to rebate me, and I insisted that I did not want a rebate because of the tax professionelle system whereby if you pay up front you have around 3 years free.

Anyway to cut a long story short all this was eventually sorted out except that RSI keep sending me mensuelle demands (with the correct tax), despite visiting and telephoning them. I was about to go again to St Brieuc to pay via cheque yet again, but tonight just out of curiousity I decided to see if I could gain access to the Net Enterprise to see if they had set me up a second trimestrielle demand and they have. Do you think I am safe enough to fill in this online form?

I much prefer it - they have no record of the payment I made manually at St Brieuc but I have a paper copy of the payment I just want to get back to normal by paying online again.