how to get rid of red bumps caused by waxing?

Tendskin. It will burn, but it'll reduce the redness. Also great for razor burn.

try Smile's PRID Homeopathic Salve which is an all natural drawing salve. It is a topical ointment formulated to ease pain, minor skin eruptions and redness. I do not have a financial interest in this product.

Bag Balm. used by dairy farmers to sooth the utter. Also Corn Huskers Lotion, good for really dry chapped skin from working outdoors in winter (where it is cold and wet)

If red bumps caused by waxing are anything like razor burn, then tea-tree oil highly diluted with water (1 to 10 ratio) would work well. Since it is an oil in water you have to shake it vigorously then quickly dip a q-tip in it. This will make it so you don't apply pure oil, which could sting quite a bit. Tea tree oil is a refreshing, natural antiseptic which makes my razor burn almost immediately disappear.

If natural remedies aren't working, you can go for the high-test stuff. Sally Hansen, Bath and Body Works, and Sephora have begun carrying medicated pads specifically for pre and post waxing that prevent and eliminate red bumps and ingrown hairs from waxing. The Sally Hansen run around 4 bucks and the Bliss ones from Sephoar can run upwards of 25. Good luck!