Well the good news is that you can reclaim those stupid charges. We have a mortgage with Platform but have been good, we had a secured loan with GE Money and they charged us countless £40 late payment charges - I am waiting for a cheque for about £1700 as we speak as I issued proceedings against them once we had managed to refinance the loan (strangely enough with Platform) and they agreed to settle.
GE did the "debt counsellor" crap with us for about the same cost and the guy who came round was more like a bailiff - told us the dire consequences of repossession (they did try once) and also told us not to pay any credit cards as they are not important. It was good fun telling the GE card people that their secured lending department had told us not to pay them
Presume that Platform are saying that if you refuse to see the debt counsellor that they will charge you anyway. But I know from when they guy came to see us he was of no help, said he could recommend stuff to GE but at the end of the day his input was not considered by them.
You could reclaim the charges now IMO - I decided to wait as it was our life's mission to pay GE off after the sh*t they caused for us. We are self employed too and I know exactly what you mean about being a few days late through no fault of your own.