Most of the charges are standing charge, sewerage, taxes etc. Your water bill seems about right. We didn't use our place for 2 years and we still got an average water bill of around 56 euros a quarter.
However, your electric sounds rather high. For the 2 years we didn't use it, our bill was 20 euros every 2 months. When we stayed there for a month, it shot up to 55 euros for the 2 months and then settled back to 20.30 euros every 2 months.
We were also with aquagest and Iberdrola. Iberdrola is extremely difficult to get hold off and you would be on the phone for ages before they answer. It is 24 hours but the English speakers appear not to work at night. If you go to the Iberdrola office in Torrevieja you may need to take an interpreter with you.
I did eventually find an email address (clientes@iberdrola.com) and they were fairly quick in getting back to me (about 4 days).