Device Booster "Benefit" is FALSE ADVERTISING!!

Discovery Vitality have FAILED in rectifying my Device Booster activation issue since 6th April 2019.... That's 4 MONTHS!!! I purchased my Garmin device and have achieved several of the weekly goals in order to earn my cash back. But my Device Booster Activation does still not reflect and I have not received a single cent back on the "benefit" that they so boldly advertise. I'm ANGRY that they think that this is OK. I have reference numbers for 3 calls I have made. SHOCKING!!