Lontok showed interested in working with Rustan's Department Store as a merchandise manager, which left Tantoco (Glecy), her family friend, in disbelief. According to her, she was interviewed twice just to make sure that she was serious about the position. In the transition, Lontok shared that the biggest challenge for her was the accounting aspect of the job, but with her dedication to learning the tricks of the trade, she got promoted to group manager.

With Tantoco's help, Lontok started her own line, which was then first known as "Criselda". From a few blouses to a full-blown department, her eponymous brand became the top-seller among the retail store's local brands.

Through her work with Rustan's, Lontok was able to regularly visit the showrooms of some of the world's greatest brands like Dior, Gucci, Louis Ferraud, YSL, Nina Ricci, and Christian Lacroix. Her own line made it around the world as well and catered to women of high-ranking positions in government or corporations, politician families, and from the high society.

Lontok's pieces have her signature look of floral embroidery, vibrant colours, and outfits accented with impeccable appliqués. She also had her fair share of prints and plains, knitwears and silks, and airy cuts that embody femininity. Moreover, her line included bags, shoes, accessories, and jewellery for women too.

This morning of September 22, 2021, Lontok sadly passed away due to cardiac arrest and health complications. Our thoughts and prayers go to the bereaved family and friends left by the prolific fashion icon who we all loved and adored. Her legacy will be remembered fondly. 

The Rustan Commercial Corporation released a statement after the news about Lontok's passing broke out, expressing the management and staff's heartfelt condolences. To quote, it said: "It was an absolute privilege knowing Criselda. She will always be remembered for her personal touch and incredible attention to detail, as a fashion icon continuously reinventing the Philippine fashion retail industry, and as a loyal and steadfast member of the Rustan family."

Zenaida Tantoco, daughter of Glecy, also shared a few words to remember the incredible creative force who graced Rustan's for many decades. "To her, every fashion show was an exciting event . . . every collection is an opportunity to create a statement," she said. "Criselda personally called and sent her own messages to those she invited, no matter how many. To her, the women she dressed were not just customers, but were, truly, her muses—her source of inspiration. She was very goal-oriented and fiercely loyal. She and my mother worked very closely together, even going on buying trips together. The roots of our relationship are deep."

Lastly, Donnie Tantoco also shared his story of working with Lontok at Rustan's for the last 30 years: "I have admired and respected how she kept setting new records, scaling new heights with her brand. What I admired the most is how she worked during the pandemic. While others were hibernating, Ms. Criselda was adapting and innovation. From evening dresses, she pivoted to beautiful clothing to be worn at home. She always had a victor and not a victim mentality. I have also never heard her say anything negative about anyone. She not only had such grace but also this unshakable equanimity and generosity."