Problems with Recommerce trade-in platform

Hello,

this 3rd party platform that handles trade-in are complete cons and thieves on top of that. Almost impossible to contact and when they finally reply they give conflicting information. I sent in a trade-in that qualifies for a bonus as advertised by Microsoft following a recent Surface purchase. At first Recommerce wouldn't recognise and refused it, then following multiple emails finally recognised it. Now they valued the trade-in at zero, despite it being worth just over £100, so essentially all they'll offer is still the £100. They are wrong btw, elsewhere it was valued at just over £100 and I went with Microsoft trade-in because of the bonus and because it was the right thing to do having just made a sizeable purchase. I wonder if Microsoft realise who they associate themselves with? It may be 3rd party, but it is through Microsoft nonetheless.