Supersonic refund outstanding after numerous follow up

I needed a router replacement urgently. Supersonic team member advised if I pay immediately they will send someone the same night to resolve, and was in contact with Linteq who is my fibre provider. They only came the next day with the wrong router, at a later time than confirmed. Linteq arrived with the correct router, and did not charge me, as they worked together, and Linteq was supposed to do the install, not Supersonic. I requested a refund more than once, sent my bank details, made numerous follow up. Been almost 3 weeks, still nothing. The incorrect router is still at my residence. This is the 2nd time in my life I wrote a review about poor service, the first review was also about Supersonic. Please sort this out, the service is unacceptable!