do apple have a spam calls app?

Apple just offers the settings suggested at Detect and block spam phone calls - Apple Support

Otherwise your better bet is to check with your carrier if they offer a spam call blocker.

I would second @shoeluvr13's suggestion that you contact your cellular provider. Most of the major carriers do provide call-blocking services, or specific apps, for this purpose. For example, AT&T provides the ActiveArmor app thru the Apple App Store.