Treadmill not working (Sheffield, Heeley, S2)

Purchased last year been using for past few months, but engine has seized not sure if because we used WD-40 instead of treadmill lubricant or used to walk on rather than run, or something els, but because of us using WD40 we think we have probably voided the warranty. So, if there is anybody out there who’s a dab hand at fixing things, this would be a great free product as we bought it for £300+ a few months ago.