Hello @Sushila2
I am sorry to hear about your experiences.
It's simply not true to say that Airbnb doesn't allow negative reviews, there are many hundreds of thousands of negative reviews of hosts and guests on the platform.
And you post is rather confusing as your review is clearly showing up on the hosts profile so hasn't been deleted (even though you admitted telling the host that you wouldn't give them a review if they gave you a full refund which is against Airbnb's policy).
Did you go to your doctor to check out what the bites actually were. There are lots of things you can get bitten by. For example, I am allergic to mosquito's and come up in bites that look similar to bed bug bites whenever I travel to a hot country.
What outcome are you looking for here? Did Airbnb refund the costs of your stay?
Normally where it can be shown that a host does have bed bugs, Airbnb will ask the host to have the listing treated and confirmation that the place is bug free.
There have been cases however, where guests have insisted that a listing has bed bugs asking for a refund and a pest control agency goes in and finds there are no bugs. In these cases hosts have been able to pass these costs onto the guests.