If the 13132 is for the closure of the surgical wound, then it is correct that it is bundled. Complex closure may be billed in addition to excisions of skin/subcutaneous lesions but the deep tissue excisions such as 21552 already include closure. The only way you can successfully appeal this denial is if the 13132 was unrelated to the surgical procedure billed with 21552.
Per the NCCI manual:
Closure/repair of a surgical incision is included in the global surgical package except as noted below. Wound repair CPT codes 12001-13153 shall not be reported separately to describe closure of surgical incisions for procedures with global surgery indicators of 000, 010, 090, or MMM. Simple, intermediate, and complex wound repair codes may be reported with Mohs surgery (CPT codes 17311-17315). Intermediate and complex repair codes may be reported with excision of benign lesions (CPT codes 11401-11406, 11421-11426, 11441-11471) and excision of malignant lesions (CPT codes 11600-11646). Wound repair codes (CPT codes 12001-13153) shall not be reported with excisions of benign lesions with an excised diameter of 0.5 cm or less (CPT codes 11400, 11420, 11440).