''
Hot 100 by
Destiny's Child's "
Independent Women Part 1". In the United States, "Case of the Ex" debuted at number 72 on
Billboard Hot 100 in the week of August 19, 2000.[1] The following week, it leaped from 72 to 57 in the week of August 26, 2000. It continued to climb the Hot 100, ascending from 42 to 31 during its sixth week, on September 23, 2000. The song reached its peak at number 2 in the week of December 2, 2000. From the weeks of December 2–16, 2000; it spent three consecutive weeks at number two. "Case of the Ex" spent 30 consecutive weeks on that chart. The song became Mýa's second non-consecutive solo top-10 hit after 1998's "
It's All About Me" (featuring
Sisqó). It remains Mýa's second-biggest and second-highest-charting single on the chart to date (she topped the chart the following year when the "
Lady Marmalade" remake featuring her,
Lil' Kim,
Christina Aguilera, and
Pink climbed to number one). "Case of the Ex" became a top-10 hit on
Billboard Hot R&B/Hip-Hop Singles & Tracks chart in the week of December 9, 2000, peaking at number ten and spent 28 consecutive weeks on that chart. It was Mýa's fifth and final top-10 hit on that chart. Globally, "Case of the Ex" debuted at number five on the
Australian Singles Chart on the week of February 18, 2001. It topped the chart and spent two consecutive weeks at number one, during the weeks of March 18–25, 2001. In total, the song spent 23 consecutive weeks altogether on the chart. It was certified platinum by
Australian Record Industry Association for shipment of 70,000 units. In the Netherlands, the song debuted at number sixty-two during the week of October 7, 2000. It reached its peak of number eight in the week of November 4, 2000, and spent 18 consecutive weeks on the Dutch
Single Top 100 chart. "Case of the Ex" peaked at number seventeen in New Zealand during the week of January 28, 2001. It debuted and peaked at number three in the United Kingdom on the week of February 10, 2001, and spent 13 consecutive weeks altogether on the chart. ==Music video==