Competitor leaving fake negative reviews

Please see these two accounts below:

https://www.amazon.co.uk/gp/profile/amzn1.account.AFRNXYP5JHFYHUMCPKLTYXOJXDTQ/ref=cm_cr_srp_d_gw_btm?ie=UTF8

https://www.amazon.co.uk/gp/profile/amzn1.account.AHSM3ACTVBS7GVQYBN36HDAJQGNQ/ref=cm_cr_dp_d_gw_tr?ie=UTF8

These are clearly fraudulent fake accounts made by our nervous competitors trying to bombard our listings with 1-star reviews, Amazon is not helping with the issue at all, I contact them daily.

Some of the listings have never even sold 1 item because of the 1-star review, so how can it be a legitimate review?

We have sold over 20 items now and all of the customers I have been in contact with are happy and will leave great reviews however they are taking a long time to show up and a lot of the listings will never be balanced out by real, positive reviews because they haven't been able to sell at all before getting an instant fake 1-star review!

Really need some urgent advice on this issue. Amazon is in no way our primary income so we can totally weather the storm for a while but it's just doesn't seem worth it when this sort of behaviour is not policed in any way shape or form.