I was two hours late picking up the car. Their hotline wasn't accessible. When I finally arrived, they told me my reservation had been canceled and charged me more than double the original price.

As you finalize getting car from BGY airport arrivals, staff will show you P3 garage which you can go there by bus number 8.

Normal insisting comprehensive insurance hasn’t been booked

Ok

Upon picking up the car I was advised I needed to pay 1000 euros deposit vis a credit card, which I do not have, so instead I was compelled to pay 130 euros for fully comp insurance that I did not want, meaning my great deal was in fact, terrible. The staff were rude and the car was downgraded from the reserved 'Golf or similar'

The counter staff was very rude. Forcing me to get additional insurance and saying that the insurance I have with easyrentcars is illegal.