Start Error-W.S.P. unit?

im absolutely gutted, i have a mercedes sprinter 311 cdi, 2004, battery went dead and then "start error" on the dash, rang mercedes £177 call out and told it was W.S.P. unit, looked on the internet and sent ecu and wsp away but unable to do anything as it was wiped clean. Rang a guy on here "williamsdiesels.com" Dean, and he told me without asking any details it was a wsp (wasted £177), i saw a unit and ecu on ebay £200 and asked him what he thought to code it all in, Dean told me it didnt need coding in and that should the ecu or wsp be faulty i could be looking at a further recover and off the road time, im a builder, fitted it regardless...... Guess what.... i broke down. I had to order a wsp £168, and Dean came out to me and programmed it in. Wasnt keen to pay his price first time, but boy do i regret it now. Sent the ecu back and guess what also, address unknown.
Cost me a fortune all il say is if you get start error on your merc cheap isnt always good. Wasted days off the road, wasted £377 and £130 on recovery, and lost a weeks worth of work, and was back to square one Needless to say Dean was laughing when he arrived. Still wouldnt drive another van, sprinters are the best.