Overcharged by Manufacturing Builders Jurong West for service

I want to acknowledge that Manufacturing Builders Jurong West has attempted to resolve this issue. However, the solution they're offering (a $425.34 store credit) isn't adequate considering I paid $425.34 for a wireless speaker that never worked properly.

Dear customer, I am reaching out regarding your recent complaint about our installation service. First and foremost, I want to extend my sincere apologies for the frustration this situation has caused you. As the Senior Customer Representative at Manufacturing Builders Jurong West, I have personally reviewed your case and have spoken with the team members involved. There appears to have been a miscommunication regarding our service guarantees, and I take full responsibility for this oversight. I have taken the following immediate actions: 1. Processed a refund of $108.50 to your original payment method 2. Added a $108.50 service credit to your account for future use 3. Implemented additional training for our staff based on your feedback Your case has been assigned reference number REF-09EA221D for any future correspondence. Please allow 3-5 business days for the refund to appear in your account. Thank you for giving us the opportunity to address this matter. Your feedback helps us improve. Sincerely, David Walker Senior Customer Representative Manufacturing Builders Jurong West