walmart drug charge policy knoxville Tennessee

 for ,well ever since walmart has had a "$4 dollar" prescription policy i have been receiving a particular prescription for 90 days for 10 dollars and it was well received .my latest trip to refill same prescription ...DOXAZOSI MESYLATE,8MG (Oral Tablets) ....i was informed that the price of this prescription had increased from aforementioned 10 dollars to $105 and change .i somehow understand that at times items must fluctuate in price and could have accepted a small increase in stride ,BUT ONE THOUSAND PERCENT IS ABSURD !I asked the assistant why and all that was given as a reason is that "hey just do this sometimes" .sucks to me ...what do you think !?