You have been prescribed ranitidine but it did not work all the time. I would like to suggest certain lifestyle modifications like taking small and frequent meals.
Avoid fatty and spicy foods, carbonated beverages, caffeine. Even alcohol and smoking can trigger indigestion
If you are obese, cut down extra calories, exercise regularly and reduce your day to day stress.
Even if with lifestyle modification, you still continue to have symptoms then revisit your physician. Doctor might change ranitidine to other group of drugs called Proton pump
As you are having chest pain and arm numbness
, i would suggest you to rule out heart causes for same. Tell your physician about same concern. ECG might be required along with physical examination.