@Rhino06uk you are talking to Sky by posting in this forum this is primarily customer to customer channel.
Have you raised a formal complaint with Sky as the ombudsman wont take your complaint until you have done that see https://www.sky.com/help/articles/how-to-make-a-complaint
If Sky cannot get Openreach to deliver the guaranteed connection speed to your hub then you will be released from contract and paid compensation at the rate Ofcom rules state. It is very rare for Sky to dispute these type of issues but if they dont agree to release you or have taken over 8 weeks since the formal complaint you can go to CISAS who act as the alternative dispute resolution service for Sky and other ISPs
The speed that is guaranteed is the speed to the Sky hub not the speed at a device. Given a common issue is speeds of wifi in the customers home which is dependant on the layout and construction type of the property they are not covered by the guarantee.
If you would like help understanding the technicalities post some details and include your hub's connection stats as explained here Find your Sky Broadband router statistics
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65inch Sky Glass, 3 Sky Streaming Pucks, Sky Ultrafast + and Sky SR213(white Wifi Max hub) main Wifi from 3 TP-Link Deco M4 units in access point mode
