Refund after final bill (no response from Bulb)

Hi. I switched away from Bulb in August 2019 and my final bill was produced on 28 August 2019. My account was in credit by over £85. The bill stated that I would be refunded by direct debit within 2 weeks. However, it has now been over 7 weeks and I have not received any money. I have tried to contact bulb on numerous times via email and phone but I am not getting an answer. I have also been made aware that I am eligible for compensation from Bulb (minimum £30) as they have not refunded the credit within 2 weeks of the final bill.

Could someone, please help? I have a bad feeling that Bulb is having issues and may just go under. I am not getting any support on emails or phone.

Many thanks,
Salman.