Where is my FREE Wi-Fi Extender ????

In April I upgraded to a 20Mbps fibre line and it was agreed that I would be receiving a FREE Wi-Fi extender - to date my service / speed on this line has been so inconsistent and a times really frustrating. I have a library of references numbers (***]Re: [0][***]Re: [0][***]FW: [***] and my query has been escalated beyond any known level to as many different departments - "Customer Value Management", "The Relevant Department", "Back Office Operators", "Fulfilment Residential" and who knows where else .....