Perhaps you have a deep seated fungal infection or have got reinfected by it.
Betadine is very harsh and should not be used on genitals. Candid B lotion is also a local antifungal. If these have not helped, it could be due to improper dose or ineffective dose.
Next Steps
Meet a dermatologist, if possible , and get examined. At times you need an oral dose of emdicines to completely eradicate fungal infections.
Health Tips
India being a hot and humid place, there are high chances of fungal infections recurring. Due to this, do not be alarmed if you get reinfected later. Its better to keep hygiene good. Keep pubic hair trimmed, wear cotton or hosiery underwear. Avoid wearing tight fitting clothes ( jeans ) for prolonged times. While sleeping weal loose cotton clothes or hosiery track suits ( NOT LYCRA ) and avoid wearing underwear at sleep