I can totally feel your pain...
Had the same situation with my hosting provider, after paying in advance for 2 years they shutted down the website due to the fact it used too much of theire system recources. I was not even at 1/100 of my allowed bandwidth usage but one thing hosting companys never tell you in theire advertisements is the way they count system usage. Every database request is counted for instance my unique visitor numbers were small:
date requests pages unique visitors
7/Nov/05 148769 1709 492
8/Nov/05 173892 2172 700
9/Nov/05 227846 1798 543
Notice that requests is a about factor 80 higher than the number of pages I got so if for instance you with your website have an avarage of let say 70 querys you get in your example for friday 54308*70 = 3.801.560 database request which is pretty high.
My hosting company said that they look at the totall server load by all sites and just give each site a procentual number to see if the site is large or below avarage. So if there are 20 sites hosted on 1 server, but the 19 are small sites with very low traffic amounts you can conclude that Imy website is allways the one which is using most of the resources. But they never tell you this when you sign up... My hosting company was by the way Hagen Hosting, so don't use them for large ammount of traffic
I did a bit of research for your site and it seems you host your pictures at a server located in germany which is owned by servage.net sounds very good if you read what they are offering but they also note in a part of theire website :
"If at any time the Customer’s website generates enough bandwidth usage to affect the performance of other customer sites on the server, we reserve the full right to terminate the Customer’s domain name without refund."
Which in my opion is the same for : "If your site is active we will shut it down even if we say we provide you 510GB data transfer a month" I really hate such misleading information. They even say theire computers are using 12GB RAM so also cpu resources are not theire reall problem.
I can only advice you to take a look at my other topic on this about coppermine for high performance websites:
http://forum.coppermine-gallery.net/index.php?topic=23663.msg108992#msg108992Further I can say I moved my actvities to godaddy.com (
https://www.godaddy.com/gdshop/hosting/shared.asp?se=%2B&ci=260) they are offering hosting plans at low rates no problems with them even after growing amounts of traffic (not as high as yours though I generate daily around 1-2GB)
Good Luck!