Email them at
info@gigspot.com and tell them you want to cancel and go direct with the MSC's. Be prepared to wait six weeks to six months for a response.
Also be prepared that they likely won't disconnect you from all of them and you'll have to attempt to contact them again. And then wait again for a response.
Yeah, Gigspot is no bueno.
Doing assignments since the days when reports were handwritten and faxed to the MSC.