How Long After Taking Rocephin Do Symptoms Of UTI Lessen?

I have a comlicated UTI it began around January 23rd and I still am fighting it today almost a month later. The culture showed 100,000 E-coli bacteria and was first treated with Ceftin 500mg 2x for 7 days and still had a problem when I stopped the medication. Rocephin usually works for me so on February 5th I was given 1gm of Rocephin in the Doctors office. Still had symptoms and went to the ER on February 15th and was given another 1gm of Rocephin and told to have 6 days of Rocephin shots administered by my clinic's nurse.Today, I'll be getting a third shot of Rocephin, yet my symptoms of a UTI persist and a test strip I did at home showed positive for leukocytes. I want to go back to ER and ask for an IV of gentamicin. Should I wait for the complete 7 days of Rocephin shots or try another antibiotic. Thank you for your help.