Terrible service received

Worst possible service ever. I ordered 3 items in September 2018. Hyperli states 5-7days delivery...it arrived over a month later and missed my sons birthday. I opened the boxes 2 weeks later as I was on training when it arrived only to find the products are defective. For the pas t 4 weeks i have been trying to have these things returned only to be told it either missed the 7 day returned policy or they cannot see the imagines uploaded. This is blatant ******* I as I did not pay to have defective products. I want my refund as its unfair to provide me with misleading adverts and claims of 7 day deliver times. I am quite disappointed as this was my first delivery purchase...I will not buy from them again nor will I ever refer them if this is the treatment a customer gets.