Incorrect order delivered

I ordered a pair of black sandals and red sandals were delivered on 8 December 2017. Despite following the correct policy in terms of requesting an exchange and numerous emails and complaints I have had no feedback to date. Zando advertise a contact number which I have tried to get through to every day since 8 December 2017!!! This contact number is never answered. I have sent mails to Zandos complaints email address and guess what - still no feedback. I cannot believe the shocking service - in fact no service at all!!!